Rod construction

ABSTRACT

A rod comprises a plurality of elongate members joined together in an assembly, with each elongate member having a generally T-shape cross-section and being formed from fibre reinforced sheet material. Each member comprises two outwardly curved members formed with first leg sections contiguously disposed and connected to form the web of the T-shape, second leg sections extending at an angle to the first leg sections, and a planar cap member spanning and connected to the second leg sections to form the cap of the T-shape. The cap member has opposite ends which define abutment faces. Each curved member has a curved radius portion between the leg sections, with the curved radius portions and the planar cap defining a space therebetween which is filled with a filler material. The cap members are joined together so that said abutment faces of adjacent cap members are contiguous, thereby forming the assembly.

FIELD OF THE INVENTION

This invention relates to rods and in particular to rods produced by amethod which enables production of a rod with a desired set ofcharacteristics when flexed.

BACKGROUND OF THE INVENTION

Flexible rods find applications in a variety of fields, for example, asfishing rods, which rods are tailored to suit particular applications.Stiffer rods are preferred for heavy fish, while very flexible rods areutilised in fly casting. A variety of materials and geometries areemployed in these applications. In fishing rod construction, cylindricalsection materials both hollow and solid have been used. Round materialspose problems in mounting thereon an aligned set of line guides. Some ofthe lightweight, flexible materials, such as hollow carbon tube, havepoor crush characteristics and poor torsional performance so that theapplication of fishing line guides to them poses problems. Theconventional technique involves binding a wire-form bracket firmly tothe rod. Too much pressure can crush a carbon filament tube. Attemptingto realign a guide by twisting it about the rod axis can result in afracture. Other rods less prone to these problems suffer disadvantagesin less desirable flexing characteristics. Construction of tube formrods with tapers is not easy.

U.S. Pat. No. 1,932,986 to Powell shows a split cane technique for rodassembly from a number of canes. A rod of this type is provided with ataper by reduction of the wedge section dimensions over the length ofthe elements of the assembly.

U.S. Pat. No. 4,582,758 to Bruce et al shows a development of the aboveutilising fibre resin reinforced plastic techniques. The cane wedge isduplicated in reinforced plastic and assembled in much the same way.

While a great variety of materials and layup techniques have been triedin the construction of rods, there is scope for improvements. It isdesirable to establish a fabrication technique that may be applied toproduce a range of rods each with preselected parameters for particularuses.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide a rod fabricationtechnique that enables rods to be produced with predetermined propertiesutilising an assembly of preformed members.

Other objects, and various advantages of the invention will hereinafterbecome apparent.

OUTLINE OF THE INVENTION

The invention achieves its objects in providing a rod comprising

an assembly of elongate members each having abutment faces whereby eachelongate member contacts its neighbor;

adjacent elongate members being joined together at their abutment faces;

characterised in that:

the elongate members have a generally T-shape cross-section with aflange capping a web section;

the assembly combines all the flanges together to establish a polygonalcross-section; and

the web sections of each elongate member being extended in a directiontowards a common axis.

The invention also provides a rod comprising:

a plurality of elongate members;

the elongate members being arranged in an assembly about a central axiswith at least one mating surface between adjoining elongate members; and

the elongate members being bonded at their mating surfaces with eachelongate member being bonded to its two neighbors about the centralaxis;

characterised in that

each elongate member comprises a composite body formed with at least onereinforcing layer with fibres or filaments of reinforcing materialextended therethrough in a predetermined pattern,

the predetermined pattern in planar form comprising a first array ofsaid fibres or filaments extended parallel to the length of the elongatemember, a second array of fibres or filaments arrayed across said firstarray and a third array, of fibres or filaments being arrayed oppositelyto the second array, relative to the first array, to cut across thefirst and second arrays: and

the reinforcing layer being folded or curved about an axis which isparallel to the central axis and the axis of the first array.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to preferredembodiments as shown in the accompanying drawings in which:

FIG. 1 illustrates an array of reinforcements utilised in the invention;

FIG. 2 shows how the laid up fibres of FIG. 1 are used to establish abasic elongate unit in accordance with the invention;

FIG. 3 shows an elongate member formed of an assembly of the units ofFIG. 2;

FIG. 4 shows an alternate elongate member formed from a unit of FIG. 2;

FIG. 5 shows an assembly of the elongate members of FIG. 5 in accordancewith the invention;

FIG. 6 shows an assembly of the elongate members of FIG. 4 in accordancewith the invention;

FIG. 7 shows a development of the elongate member of FIG. 3, and

FIG. 8 shows a development of the elongate member of FIG. 4.

PREFERRED EMBODIMENTS

In construction of rods in accordance with the invention, advantage istaken of the properties of reinforced materials such as fibre reinforcedplastics. In layup of the material, the orientation of the fibres orfilaments is a concern and FIG. 1 illustrates a particular pattern whichis useful.

With reference to FIG. 1, a triaxial pattern is developed withlongitudinally extended fibres or filaments 11 of the assembly 10 beingthose which in use will extend in a direction which is parallel to theelongate axis of the rod.

Extended across the arrays 11 are two further array of fibres orfilaments, one to the left, array 12, the other to the right, array 13.Arrays 12 and 13 extend acutely to the direction of array 11 and to eachother.

In production of the pattern of reinforcement of FIG. 1, the assembly 10may be effected with layup of a cloth with a triaxial weave as shown orby overlap of three layers, each comprised of generally parallel fibresor filaments. In use of the latter, a layup may be established with afirst layer of fibres oriented as in array 11 overlaid by second andthird layers oriented each in one of the directions of arrays 12 and 13.Preferably the three layers are overlaid by a fourth array having theorientation of array 11, to create a sandwich of crossed fibres such as12 and 13 between two parallel layers oriented along what will be theelongate axis of the rod. If desired, this pattern might be repeatedwith a succession of crossed layers sandwiched between layers orientedparallel to the elongate axis of the rod. Alternately, an array such as12 might be sandwiched between two such as 11, with an array such as 13superimposed and capped by another layer such as 11 to provide a fivelayer composite.

In production of the above, the aim is to include within the layup, apattern of fibres or filaments which contains the elements of FIG. 1 andexhibits a degree of symmetry about the elongate axis.

In production of a rod as will be described below, layup of an assemblyof fibres or filaments as in FIG. 1 is made with a geometry of the typeindicated in FIG. 2 whereby an elongate member, the basic unit of a rodin accordance with the invention, is produced.

An elongate member 14 is produced with a curve about its elongate axis15 which produces a U or generally V shape member with a base of chosenradius of curvature. The actual geometry of the elongate member 15 sofar as its sectional view is concerned, is determined by the propertieswanted in the completed rod. In layup of the elongate members, thepattern 10 of FIG. 1 exists in the member 14 with the array 11 of fibresor filaments extended along the members elongate axis 15. In thisconfiguration, the fibres or filaments are curved or bent about thecurve of the U or V shape of the member.

In production of the elongate member of FIG. 2, the arrays of fibres orfilaments are set within a suitable material to create a rigid elementhaving the geometry shown.

In FIG. 3 is shown a composite elongate member 20 made from an assemblyof two of the members of FIG. 2, 16 and 17, which form the leg of aT-shape element capped by a reinforced layer 18 which is preferably inaccordance with FIG. 1 oriented with array 11 along the elongate lengthof the composite member. The hollow center 19 of the composite membermay be filled with an impregnated material of compatible character tothose materials which are chosen for the elements 16 to 18. It may bedesirable that the pattern of filaments in the two curved elements bearranged to each be a mirror image of the other.

FIG. 4 shows an elongate member 24 which has a generally V-shape, withthe angle of the arms 42 and 43 being set at 60° to provide the assemblyas described below with reference to FIG. 6. The V at the apex may beproduced by rolling over a mandrel, machining, etc.

FIG. 5 shows a rod 22 which is an assembly of six of the elements ofFIG. 3, oriented as shown with the legs of the respective T-shapedmembers 23 to 28 extended to the center of the rod and the caps of theT-shapes mated to form a hexagon. This geometry is particularly suitedto production of a fishing rod. In other applications, the number ofelements might be varied to produce other polygonal assemblies.

In production of the assembly of FIG. 5, the edges of the caps of theT-shape members in accordance with FIG. 3 are machined at an appropriateangle to provide mating surfaces whereat bonding may be effected so asto produce the requisite polygonal structure. The legs of the T-shapes,if it is chosen extend them to the Center may be also machined at anangle to provide mating surfaces at which bonding may be effected.

FIG. 6 shows how the member of FIG. 4 may be assembled to produce apolygonal structure. The assembly 29 of FIG. 6 comprises six members 30to 35 assembled with their arms butted and bonded together. Inproduction of a polygonal assembly other than a hexagon, all that isrequired is that the member of FIG. 4 be produced with its arms 42 and43 at a different angle appropriate to the chosen geometry. The assemblymay have a winding thereabout to provide flat outer surfaces.

In production of the assemblies of FIGS. 5 and 6 a fair degree of freespace exists, and FIGS. 7 and 8 show adaptations of the members of FIGS.3 and 4 which utilise this free space to good purpose.

FIG. 7 shows a member 36 with infills 37 and 38 which converts theT-shape, to a wedge shape with the angle of the wedge determined by thenumber of elements to be assembled to create a chosen polygonalgeometry. The infills 38 and 37 serve to encompass the leg 44. Inbending the rod in a plane through the leg 44 to compress the leg, thetendency for the leg is to buckle. The pressure of the infills about theleg oppose this and add to the resiliency of the rod. The tendency tobuckle may be resisted by an increased radius of curvature in theelements 16 and 17. In a rod which is loaded to one end, strength mightbe provided with a taper to larger dimensions, but if only the depth ofthe leg is increased, the tendency to buckle will be greater. Thislatter effect is compensated for by increasing the radius of curvatureof the elements 16 and 17 as the dimensions increase.

In FIG. 8, the infill 41 in the open V of member 39 provides a flatouter surface such that in assembly of the members to produce the rod 29of FIG. 6 there results a polygonal body with flat outer surfaces whichare then convenient mounting surfaces for features such as the lineguides of a fishing rod. A more solid outer surface may be establishedwith a winding thereabout. The provision of the flat surface enables aline of guides to be mounted along the rod with the guides establishedin proper linear alignment without any of the difficulties oradjustments required in making rods from cylindrical rods.

It is possible to provide rods using the above techniques with a tapertherealong. An element such as the member of FIG. 4 may be tapered bybeing placed apex down in the groove of a flat, which groove is machinedwith a progressive change in depth so that the member lies therein witha tapered length of material projected above the flat, which, if it beground off down to the flat, leaves a length of member 24 in the groovewhich is tapered. Assembling the requisite number of these elementsproduces a tapered rod much as is usual in the production of taperedsplit cane rods. In the same way a member such as 36 of FIG. 7 may bemachined over its length to reduce the area of its wedge to produce ataper.

In preparation of a rod in accordance with the above describedproduction techniques, the physical properties of the rod may beselected by choice among various parameters. In preparation of theelements of the T section, for example, the radius 45 (see FIG. 3) is acritical factor. An increase in this radius produces rods with a slowaction when their return from a bent configuration is considered. Adecrease produces a crisper action which, in the case of fishing rods,provides the action desired in a fly fishing rod.

In preparation of the array of fibres or filaments, a choice ofmaterial, fibre diameter, number of fibres per layer, number of layers,in addition to the radius of curvature, affects the qualities of therod. So to does the nature of the fillers, the bonding materials ortechniques employed to unify the assembly. However, in construction ofrods, the factors which are most significant to the character of the rodare its triaxial reinforcement patten and the radius of curvature workedinto the pattern in production of the generally T and V shape sectionsused to construct the rod.

In production of fishing rods, the quality of the rod will be affectedby the choice of T or V elements for the assembly. T-shape elements aremore useful for game fishing rods whereas the V-shape may be more usefulfor a lighter type of fishing rod.

Rods produced by the above means make economical use of exotic fibreswith a more crush proof construction. In flexing, the rods of theinvention provide increased power with the sensitivity that a fishermanrequires to be able to be retained. The invention enables production ofa light rigid structure which when tapered enables the action of the rodto be moved to a region therealong to enable the rod to be tailored forspecific purposes. A slow taper may move the action of the rod inflexing to a middle part whereas a fat taper will move the action to thetip.

In a preferred form of the invention the rod comprises a bonded carbonfibre structure whose elements are bonded together by a bonding agentsuch as a resin adhesive with high mechanical and dynamic strength. Aprepreg material might be provided to fill out the hollow cure of theT-shape section. A foam material might fill out hollows of the assembly.A man skilled in the art will be aware of the range of materials thatmight be drawn upon in fabrication of a rod in accordance with theinvention. The actual combination of materials will depend upon the usethe rod is put to, the environment it must endure, and factors such asweight, cost, availability of materials, etc.

In preferred forms, carbon fibres may be bonded by epoxy resin.Polyurethane and polyvinylchloride foams may be used as fillers. Glassand carbon fibre windings may be wrapped about the outer surfaces andbonded with epoxy resins. Depending on uses and loadings, any of thevast range of fibres, bonding agents, fillers and windings may find usein performance of the invention.

I claim:
 1. A rod comprising a plurality of elongate members each havingabutment faces which permit elongate members to be contacted and joinedtogether in an assembly wherein:each elongate member has a generallyT-shape cross-section and is formed from fibre reinforced sheetmaterial, each member comprising two outwardly curved members eachformed with first leg sections contiguously disposed and connected toform a web of the T-shape, and second leg sections extending at an angleto said first leg sections, and a planar cap member spanning andconnected to said second leg sections to form the cap of the T-shape,said cap member having opposite ends which define abutment faces, eachcurved member having a curved radius portion between said leg sections,said curved radius portion and said planar cap defining a spacetherebetween which is filled with a filler material; said first legsections of said elongate members extending in a direction towards acommon axis; and said cap members are joined together so that saidabutment faces of adjacent cap members are contiguous, thereby formingsaid assembly.
 2. A rod as claimed in claim 1 wherein the T-shapedelongate members are reduced in cross-section towards one end such thatsaid assembly is tapered towards said end.
 3. A rod as claimed in claim1 wherein each elongate member has areas on either side of said web andbelow said cap, each said area being outwardly defined by a planepassing through the ends of said first and second leg sections, saidareas being filled with a filler material that produces, in section, awedge shaped member whose tapered faces can be butt joined to adjacentelongate members similarly formed.
 4. A rod as claimed in claim 1,wherein each curved member has a longitudinal axis and comprises acomposite body formed with at least one reinforcing extendingtherethrough in a predetermined pattern which in planar form comprises afirst array of fibres or filaments extending parallel to the length ofthe curved member, a second array of fibres or filaments arrayed acrosssaid first array, and a third array of fibres or filaments arrayedoppositely to the second array and cutting across both the first andsecond arrays; and wherein the reinforcing layer is folded or curvedabout an axis which is parallel to said longitudinal axis and said firstarray.
 5. A rod as claimed in claim 4, wherein the elongate members arereduced in cross-section towards one end and their assembly produces arod that is tapered to that end.